Firearm magazine



FIG. 1 is a right side view of a firearm magazine, showing my new design;

FIG. 2 is left side view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is front, right perspective view thereof;

FIG. 6 is a rear, left perspective view thereof; and,

FIG. 7 is a front view thereof.

The features shown in broken lines form no part of the claimed design. 

CLAIM The ornamental design for a firearm magazine, as shown and described. 